Anti-retropulsion systems and methods

ABSTRACT

An anti-retropulsion device comprising: an expandable segment; a distal collar positioned distally of the expandable segment; and a proximal collar positioned proximally of the expandable segment; wherein the expandable segment has a corresponding plurality of expandable members, and wherein each of the expandable members is configured to expand or contract radially and circumferentially in correspondence with a change in spacing between the distal collar and the proximal collar.

FIELD

The present teachings relate to a system for preventing retropulsion ofa body and a method for deploying the system.

BACKGROUND

This application, and the innovations and related subject matterdisclosed herein, (collectively referred to as the “disclosure”)generally concern systems and methods related to reducing or eliminatingretropulsion of a body or other debris within a body lumen during asurgical procedure. Such systems and methods are sometimes referred toas “anti-retropulsion” systems and methods. As but one example ofsystems and methods, of an innovative anti-retropulsion device can beconfigured and/or used to reversibly occlude a ureter during a urologicprocedure to remove ureteral calculi (“kidney stones” that have droppedinto the ureter from a corresponding kidney), e.g. duringureterolithotripsy. Current systems used to prevent anti-retropulsionmay become damaged during a procedure and thus are not easily retractedor cease to prevent retropulsion of a body of debris. Some system oncedeployed from a 1-D state to a 3-D state cannot be compressed and easilyretracted. Other systems have a generally 2D configuration and requireadditional steps to be performed to remove the system when the procedureis completed.

An example of a system is available from Boston Scientific and offers aStone Cone™ Retrieval Coil. An example of another system is availablefrom Cook Medical and offers a NTrap® device. Another example of asystem is available from Percsys and offers the Accordian® (see U.S.Pat. Nos. 7,462,183; 7,879,066; and 7,883,516 all of which areincorporated by reference herein for all purposes). Yet another exampleof a system is available from Boston Scientific and is sold under thename Backstop. Examples of some anti-retropulsion systems that may beused may be found in U.S. Pat. Nos. 6,610,077; 7,097,648; and 7,214,229all of which are incorporated by reference herein for all purposes.

Despite prior proposals, anti-retropulsion devices have not been widelyadopted by surgeons. Accordingly, there remains a need for effective,easy-to-use, and safe anti-retropulsion systems, apparatus, and methods.It would be attractive to have an anti-retropulsion system and method sothat the anti-retropulsion system is extendable behind debris and can beretracted and removed from behind the debris. It would be attractive tohave an anti-retropulsion system that is expandable to fill an entirecross-section of a body lumen. It would be attractive to have ananti-retropulsion system that can be used with a laser, a green laser,an ultrasonic device, or a combination thereof.

SUMMARY

The present teachings meet one or more of the present needs byproviding: an anti-retropulsion device comprising: an expandablesegment; a distal collar positioned distally of the expandable segment;a proximal collar positioned proximally of the expandable segment;wherein the expandable segment has a corresponding plurality ofexpandable members, wherein each of the expandable members is configuredto expand or contract radially and circumferentially in correspondencewith a change in spacing between the distal collar and the proximalcollar.

The present teachings provide: an anti-retropulsion device comprising:an elongate tubular sleeve defining an outer wall having: a proximalwall portion defining a first plurality of apertures, each of the firstplurality of apertures having: a proximal end, and a distal end; adistal wall portion longitudinally spaced from the proximal wallportion, the distal wall portion defining a second plurality ofapertures having; a proximal end, and a distal end; and an intermediatewall portion located between the proximal wall portion and the distalwall portion; wherein the proximal end and the distal end of each of thefirst plurality of apertures, the second plurality of apertures, or bothare positionally offset in an ordinate direction, wherein each of theproximal ends of the second plurality of apertures are offset in anordinate direction from each of the distal ends of the first pluralityof apertures; and an apparatus configured to urge a distal end of theelongate tubular sleeve toward a proximal end of the elongate tubularsleeve.

The present teachings provide: a method comprising: positioning ananti-retropulsion device at a desired location and moving a core wire sothat a distance between a distal collar and a proximal collar is reducedand an expandable portion is expanded.

The present teachings provide an anti-retropulsion system and method sothat the anti-retropulsion system is extendable behind debris and can beretracted and removed from behind the debris. The present teachingsprovide an anti-retropulsion system that is expandable to fill an entirecross-section of a body lumen. The present teachings provide ananti-retropulsion system that can be used with a laser, a green laser,an ultrasonic device, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The innovations disclosed herein overcome many problems in the priorart. Unless specified otherwise, the accompanying drawings illustrateaspects of the innovative subject matter described herein.

FIG. 1 illustrates a side-elevation view of an anti-retropulsion device(“ARD”) operably coupled with guidewire in an insertion configuration.

FIG. 2 illustrates a side-elevation view of the ARD shown in FIG. 1 in adeployed state, as after insertion from a lumen.

FIG. 3 illustrates a magnified isometric view from alongside a sheath ofthe ARD shown in FIG. 1, in an insertion state.

FIGS. 4A and 4B illustrate an example of a radially expanded andlongitudinally contracted ARD in a “deployed state”. FIG. 4A shows anisometric view of the ARD and FIG. 4B shows an end-elevation view of theARD.

FIG. 5 illustrates an isometric view of another ARD in a transformationto a deployed state.

FIG. 6 illustrates an isometric view of the ARD shown in FIG. 5 in aninsertion state.

FIG. 7 illustrates several details of an embodiment of a sheath of anARD.

FIG. 8 illustrates several details of another embodiment of a sheath ofan ARD.

FIG. 9A-9K illustrates a sequence of isometric views of an expandablesegment of an ARD as disclosed herein. The sequence of views showsseveral intermediate configurations of the expandable segment as itradially expands and axially contracts from an insertion state to adeployed state.

FIG. 10A1-10D3 illustrates several alternative configurations ofradially expanded ARDs.

FIG. 11 illustrates an alternative embodiment of an ARD configured tooverlie a guidewire.

FIG. 12 illustrates another alternative embodiment of an ARD havingseveral expandable segments with differing lengths, forming a“cone-shaped” ARD in a deployed state.

FIG. 13 illustrates another alternative embodiment of an ARD havingseveral expandable segments with differing lengths.

FIG. 14 illustrates an alternative embodiment of an ARD having severalexpandable segments with material removed from one or more expandablemembers to promote buckling of the respective one or more expandablemembers (and/or the corresponding expandable segments) in a selectedorder.

FIG. 15 illustrates another alternative embodiment of an ARD havingseveral expandable segments with material removed from one or moreexpandable members.

FIG. 16 illustrates an alternative embodiment of an ARD, in an insertionstate, with an expandable segment having several fiber strands formingthe corresponding expandable members.

FIG. 17 illustrates the ARD shown in FIG. 16 positioned in a deployedstate.

FIG. 18 illustrates an alternative embodiment of an ARD with anexpandable segment having a mesh configuration.

DETAILED DESCRIPTION

The features and advantages of disclosed systems and methods will becomemore apparent from the following detailed description, which proceedswith reference to the accompanying drawings, wherein like numerals referto like features throughout the drawings and this specification. Thefollowing describes various principles related to reducing oreliminating retropulsion of a foreign body or other debris within a bodylumen during a surgical procedure. Systems, apparatus and methodsdescribed in relation to any particular applications, configurations, oruses, are mere examples incorporating one or more innovative principlesdisclosed herein, and are used to illustrate one or more aspects of theinnovative principles. Accordingly, systems, apparatus, and methodsdifferent from those shown and described herein can embody suchinnovative principles, or can be used in applications not describedherein in detail. Accordingly, such alternative embodiments also fallwithin the scope of this disclosure. Mechanical anti-retropulsiondevices (ARDs) can geometrically transform from an insertion state, orconfiguration, to a deployed state, or configuration. In an insertionstate, a mechanical ARD may have a dimension small enough, at leastmeasured along one coordinate direction, to pass through a gappositioned between a body of debris within a lumen (e.g., ureteralcalculi, or a “stone”) and a nearby wall of the lumen (e.g., a ureter).After being positioned, at a desired position, distally of the body ofdebris, the mechanical ARD may be activated (e.g., expanded, unfurled)to transform its geometry from the insertion state to a deployed state,in which the mechanical ARD has sufficiently large dimensions transverseto the lumen (e.g., measured along at least two coordinate directions)to at least partially occlude the lumen (e.g., to obstruct, or preventthe passage of, a stone from retrograde movement beyond the ARD, asduring lithotripsy). Such an obstruction may block a ureter, and preventa stone from moving in a retrograde direction past the radially expandeddevice.

Geometric transformation of mechanical ARDs may be summarized (orclassified) according to their respective geometric abstractions, asfollows:

-   -   One-dimensional (“1-D”): if an elongate structure is        sufficiently slim (e.g., has a sufficiently large dimension        along one coordinate direction relative to the other two        coordinate directions) in comparison with a characteristic        dimension of a lumen (e.g., a diameter of a ureter), such as,        for example, a guidewire, the structure can be considered as        having a 1-D geometry in the abstract, with a “long” dimension        extending along a longitudinal axis of the guidewire;    -   Two-dimensional (“2-D”): if a structure has two dimensions along        two coordinate directions, respectively, that are substantially        larger than a third dimension along the respective third        coordinate dimension, such as a thin membrane, the structure can        be considered as having a 2-D geometry in the abstract. (A        structure having a 2-D configuration, if placed across (e.g.,        transversely relative to) a lumen can obstruct the lumen        similarly to a diaphragm).

Some apparatus disclosed herein may transform a respective configurationfrom an insertion state to a deployed state. In the deployed state, theapparatus can be relatively less prone to damage (e.g., as from laserenergy) compared to conventional ARDs. As well, the ARDs of theteachings herein may be relatively safe and have an acceptably low cost.

In addition to general requirements for devices of in-patient usage,such as biocompatibility, disclosed systems and methods can have one ormore of the following characteristics:

-   -   (1) Reliable, able to keep the debris (e.g., stone) in place, to        localize the debris, or to limit the extent of retropulsion        during the procedure;    -   (2) Radio-opaque for tracking;    -   (3) Resistant to damage from a laser or other energy source,        e.g., a mechanical lithotripter;    -   (4) Relatively safe for patient even, e.g., even when directly        illuminated by Ho:YAG laser beam;    -   (5) Readily deployable, reversible, and removable (e.g., quick        retrieval of such a device from the ureter is possible), at any        time during a procedure (e.g., lithotripsy);    -   (6) In certain embodiments, prior to insertion, the device        typically has an outer-diameter (“OD”) similar to a guidewire OD        (e.g., about 1.0 mm (3 Fr));    -   (7) In certain embodiments, after insertion, able to span a        lumen as large as about 10.0 mm (30 Fr) inner-diameter (“ID”);    -   (8) self-adjustable to lumen size;    -   (9) In addition to reducing or eliminating retropulsion of an        debris, some disclosed apparatus can be used to retrieve (e.g.,        remove) all or part of the debris, or otherwise manipulate a        target;    -   (10) During retrieval, able to automatically detent for the        purpose of, e.g. avoiding over stressing the corresponding lumen        (e.g., ureter) in narrow passages; and    -   (11) Relatively low cost and/or disposable.

A mechanical ARD in an insertion state may have an elongate (“1D” or“generally linear”) or a substantially planar (“2D”) configuration. Ineither instance, the ARD may be substantially thin in an insertionconfiguration, allowing the ARD to bypass a stone to reach a spacebehind it, while not pushing the stone in a retrograde direction alongthe lumen. For example, before being transformed into a configurationthat occupies a substantial space, or volume, (e.g., to form a “plug” toblock a stone's retrograde path), the ARD may have a relatively small3-D configuration (e.g., a “dot”), a thin, elongate configuration (e.g.,a “wire”), or a thin, substantially planar structure (e.g., a furled“banner”). As for material, an ARD may be made of a metal, a polymer, orboth in the form of tube, mesh, fiber, or a combination thereof, orother materials discussed herein. The expandable portion can be a tubeof a selected material, (e.g., metal, plastic, or polymer film, or abundle of natural or synthetic fiber wrapped around into a tubularshape).

As used herein, the term “insertion configuration” or “insertion state”means a configuration suitable for inserting (or removing) ananti-retropulsion device in a body lumen. As used herein, the term“deployed configuration” or “deployed state” means a configurationsuitable for performing an intended occultation localization functionwithin a body lumen. In a deployed state, the distal collar and theproximal collar may be urged apart from each other. In one example, thedistal collar may be fixedly coupled to the distal end of the expandableportion of the ARD and the proximal collar may be fixedly coupled to theproximal end of the expandable portion, allowing the expandable portionto longitudinally expand and radially contract as the spacing of thedistal collars and the proximal collars changes relative to each otherso that the ARD is changed from an insertion configuration to a deployedconfiguration.

The ARD of the teachings herein may have any configuration so that theARD may be placed behind a body of debris and expanded upon achieving adesired location behind the body of debris. The ARD when in theinsertion configuration may have a largest dimension in a longitudinaldirection (e.g., along a longitudinal axis or length). The ARD in aninsertion configuration may generally be 1D (e.g., have a length in thez-direction and be substantially flat in x- and y-directions). The ARDwhen in the insertion configuration may have a largest dimension (otherthan a length) that is sufficiently small so that the ARD may fitthrough a gap. For example, the largest dimension may be across-sectional length. The largest dimension of the ARD (other than thelength) in the insertion configuration may be substantially constantalong the length and/or longitudinal axis. The largest dimension mayvary along the longitudinal axis of the ARD, the length or the ARD, orboth. The largest dimension (other than a length) in the insertionconfiguration may be about 0.2 mm or more, about 0.5 mm or more, orabout 1.0 mm or more. The largest dimension (other than a length) in theinsertion configuration may be about 5 mm or less, preferably about 3 mmor less, or more preferably about 2 mm or less. Preferably, the largestdimension is a dimension from about 0.7 mm or about 1.3 mm and morepreferably from about 0.8 mm to about 1.2 mm.

The ARD may have a largest dimension (other than length) (e.g., across-sectional length) in the deployed configuration that issufficiently large that the lumen is completely filled, the body ofdebris is immobilized from retrograde movement; the lumen is notdamaged, or a combination thereof. In a deployed state, the expandedportion of the ARD may occupy a three-dimensional (“3-D”) volume (e.g.,expanded radially and circumferentially in response to a longitudinalcontraction) that is large enough to prevent debris from moving in aretrograde direction (or minimize the extent to which the debris canmove in the retrograde direction). For example, the ARD may preventmovement of debris as forces are applied to the debris during a removalprocedure. In some embodiments, the occultation may be sufficient toallow the expanded portion of the device to collect the stone (ordebris) fragments and/or to facilitate their eventual removal from theoperation site so that the ARD can be used as a “stone basket” to removedebris from the operation site. A geometric transformation from aninsertion state to a deployed state may be reversible, promotingrelative patient safety by allowing the device to be removed during orafter a surgical procedure.

The ARD may have a largest dimension (other than length) in the deployedconfiguration that is about 3 mm or more, preferably about 5 mm or more,more preferably about 8 mm or more, or even more preferably about 10 mmor more. The ARD may have a largest dimension (other than length) in thedeployed configuration that is about 20 mm or less, about 15 mm or less,or about 12 mm or less. The largest dimension (e.g. cross-sectionallength) may be from about 7 mm to about 13 mm, preferably from about 8mm to about 12 mm, and more preferably from about 9 mm to about 11 mm.The ARD may have a largest dimension (other than length) in the deployedconfiguration that varies along the length of the ARD. For example, theARD may have a largest dimension of about 10 mm on a distal end and alargest dimension of about 8 mm on a proximal end, or vice versa. TheARD may be comprised of one or more expandable segments and eachexpandable segment may have a different largest dimension when in thedeployed configuration. For example, the ARD may have five expandablesegments and the largest segment may be about 10 mm and the smallestsegment may be about 7 mm and the length of the segments may taperbetween the first segment and fifth segment. In another example, thethird segment may be the largest segment and may have a length of about10 mm and the first and fifth segments may have a length of about 8 mmand the second and fourth segments may have a length of about 9 mm. Thelargest dimension of the ARD (other than length) may be variable so thatthe ARD varies to match the size of the lumen. The largest dimension ofthe ARD (other than length) in the insertion configuration and thedeployed configuration may be a cross-sectional length (e.g., diameter).The ARD may include one or more insertion cones, one or more sheaths;one or more core wires; one or more collars (e.g., distal collar,intermediate collar, proximal collar, or a combination thereof); or acombination thereof.

The one or more insertion cones may be any structure that has agenerally tapered shape that assists an ARD in fitting through a gapbetween a wall of a body lumen and debris in the body lumen. The one ormore insertion cones may have a point and taper to the same size as thesheath in the insertion configuration. The one or more insertion conesmay include a through hole so that one or more devices may pass throughthe insertion cone, the ARD, or both. For example, a core wire, aguidewire, or both may pass through the insertion cone, the ARD, orboth. The one or more insertion cones may have a conical shape, atapered shape, a blunt tip, a rounded tip, an angled tip, flat tip, or acombination thereof so that the insertion cone assists in guiding theARD through a gap. The insertion cone may include a collar, may be acollar, may assist in locking a collar to a sheath, or a combinationthereof. The insertion cone may cover an insertion end of a sheath sothat the insertion end of the ARD is smooth and may be free of an edgeto catch and prevent insertion movement. The insertion cone may be adiscrete piece, may be part of the sheath, may be interconnected withthe sheath and the core wire, or a combination thereof.

The one or more sheaths have both an insertion configuration and adeployed configuration. The one or more sheaths in the insertionconfiguration may have a dimension that is sufficiently small so thatthe one or more sheaths fit through a gap between a piece of debris anda lumen wall. The one or more sheaths may be an elongate tubular sleeve.Before transforming from an insertion configuration to a deployedconfiguration, an innovative ARD may have a generally “tubular” (e.g.,annular, cylindrical) elongate shape. Although described as “generallytubular”, such elongate structures may have slits, holes, or bothextending partially or wholly through a portion of the sheath (e.g., anannular wall). Other cross-sectional shapes apart from round or annularcross-sections are possible. Examples of a generally tubular, elongatestructure is a goose neck spiral, a wire woven jacket, a geometry cutfrom a tube or laid out by individual filaments, the like, or acombination thereof. An outer diameter of a generally tubular, elongatedevice, in an insertion state, can be about the same as a sheath used todeliver the device to a surgical site (e.g. about 1 mm). The device mayhave a substantial length, providing a relatively high dimensionalaspect ratio. Such an elongate device may be characterized as having a1-D configuration in the insertion state. The one or more sheaths mayhave an outer wall, a hollow interior region, one or more expandableportions, one or more non-expandable portions, or a combination thereof.

The sheath may include one or more expandable portions, one or morenon-expandable portions, or both. Preferably, the sheath includes anon-expandable portion on each terminal end and two or more expandableportions therebetween. The sheath may be free of non-expandableportions. The expandable portions, the non-expandable portions, or bothmay include a hollow interior region.

The hollow interior region may extend axially through the longitudinalaxis of the sheath. The hollow interior region may taper along thelongitudinal axis of the sheath. The hollow interior region may beseparated by internal dividing walls. For example, the one or moresheaths may be divided into three discrete hollow interior regions bytwo internal dividing walls that reduce a size of an opening in thesheath. The outer wall of the one or more sheaths in the insertionconfiguration may have a generally circular cross-section, an ovalcross-section, a diamond cross-section, a malleable cross-section, or acombination thereof so that the one or more sheaths fit through a gap.The one or more sheaths have a distal end region, a proximal end region,and an intermediate region between the distal end region and theproximal end region. The one or more sheaths may be made of anybiocompatible material. The one or more sheaths may be comprised of aplurality of fibers made from a material discussed herein. The fiber maybe combined together in a manner so that upon contraction of a collarthe fibrous sheath expands. The one or more sheaths may be made of amaterial with sufficient rigidity that the material may be inserted bybeing pushed or pulled. The one or more sheaths may be made of amaterial with sufficient elasticity so that the material bends, folds,deforms, buckles, or a combination thereof when a force is applied. Theone or more sheaths may be made of a material with sufficientflexibility so that when all or a portion of the sheaths contacts a wallof a lumen the sheath deforms so that the lumen is not damaged, injured,or both. The one or more sheaths may be made of a natural material, asynthetic material, a metal, a polymer, an elastomer, polyethylene,polyethylene terephthalate, a polyamide, or a combination thereof. Theexpandable portions of the one or more sheaths may include one or moreslits, apertures, cuts, or a combination thereof (hereinafter referredto as “slits”) and preferably a plurality of cuts, apertures, slits, ora combination thereof.

The one or more slits may be located at any location along thelongitudinal axis, an outside (e.g. circumference), or both of thesheath. The one or more slits may be located in the distal end region,the proximal end region, the intermediate end region, or a combinationthereof. The one or more slits may be grouped together around anoutside, at a region along the longitudinal axis, or both of thesheaths. Preferably, at least one group of slits is located in eachregion. More preferably, the proximal end region includes one group, thedistal end region includes one group, and the intermediate regionincludes three groups of slits.

Each group of slits may include one or more slits. Preferably, eachgroup of slits is a plurality of slits that are circumferentially spacedapart around an outside of the sheath. Each group of slits may includeone or more, two or more, three or more, four or more, preferably fiveor more, or even more preferably six or more slits. The number of slitsmay be directly proportional to the number of expandable members in eachexpandable segment. The number of slits may be inversely proportional tothe width of each expandable member. For example, a segment including 3slits will have an average slit width of about 120 degrees, whereas asegment including 6 slits will have an average slit width of about 60degrees.

The “slit” (or aperture, sometimes referred to as a “cut”) may beoriented at an oblique angle relative to the tube's longitudinal axis(e.g., forms a portion of a helix). Depending on the material thatcomposes the tubular structure, the oblique angle may help theexpandable components cover, or extend across, the lumen's cross-sectionin a deployed state. For example, the plurality of longitudinally spacedsegments can correspond to an expanded configuration suitable forreversing the transformation (e.g., for collapsing from an expanded,deployed state back to an extended, insertion state). For example,longitudinally separated, expanded members otherwise might becomeentangled with each other and be hard to untangle when attempting toremove the ARD. Respective expandable members corresponding tolongitudinally adjacent segments of an ARD may be circumferentiallyoffset from each other. For example, each respective longitudinallyadjacent segment can define a corresponding plurality of longitudinallyextending apertures (or slits), defining a corresponding plurality ofexpandable members having a respective proximal end and a respectivedistal end. The oblique angle of the slits may be a circumferentialangle between a proximal end and a distal end of each slit that may beas much as about 180. For example, a suitable offset angle may bebetween about 30 degrees and about 90 degrees, or between about 50degrees and about 70 degrees. In some embodiments, a circumferentialangle between a proximal end and a distal end of a selected slit can beabout 60 degrees. The circumferential angle between a proximal end and adistal end of a slit may be about 5 degrees or more, about 8 degrees ormore, about 10 degrees or more, about 12 degrees or more, or even about15 degrees or more. The circumferential angle may be about 90 degrees orless, about 75 degrees or less, about 60 degrees or less, about 45degrees or less, or about 30 degrees or less. For example, a proximalend of a slit begins at a 0 degree location and the sheath is rotatedabout 60 degrees to the distal end so that the slit has acircumferential angle of about 60 degrees. Each segment of the sheathmay include one or more slits around the outside of the slit and each ofthe slits may have a different circumferential angle. Preferably, eachof the slits has the same circumferential angle.

The expandable members corresponding to each of the segments may beoffset in a circumferential direction from the expandable memberscorresponding to a respective adjacent longitudinally spaced segment. Bycircumferentially offsetting longitudinally adjacent expandable members,the respective “petals” formed from expanded members can becircumferentially offset from each other, substantially filling acylindrical or conical volume and preventing the formation oflongitudinally extending gaps between circumferentially adjacent“petals”. A substantially filled cylindrical or conical volume may blocka body lumen and prevent debris from moving past the volume.Longitudinally adjacent segments may be circumferentially offset fromeach other by a selected angle. An angle of circumferential offsetbetween respective adjacent proximal ends of longitudinally adjacentslits, A_(s), can be calculated from A_(s)=360/(S*N), where S is thenumber of expandable members in a given segment, and N is the number ofsegments. For example, in a component having 5 segments, with eachsegment defining 6 expandable members, a circumferential offset betweenrespective proximal ends of longitudinally adjacent expandable memberswill be about 12 degrees. The circumferential offset may be about 5degrees or more, about 8 degrees or more, about 10 degrees or more,about 12 degrees or more, or about 15 degrees or more. Thecircumferential offset may be about 30 degrees or less, about 25 degreesor less, or about 20 degrees or less. The amount of circumferentialoffset may be dependent upon the number of expandable members in eachsegment.

Twisting the ARD, the sheath, or both during deployment can introducesuch an angle between adjacent, radially expanded members, and can varythe cross-section coverage achieved by the expanded component (i.e., atwist angle). The twist angle may be any angle that assists insufficiently filling an inner volume of a body lumen. The twist anglemay be sufficiently large so that the deployed expandable members (i.e.,petals) fill the inner volume of a body lumen and the body lumen is freeof any longitudinally extending gaps between circumferentially adjacentpetals. The twist angle may be sufficiently large so that eachexpandable member has an upper portion and a lower portion that areseparated, but the not so large of a twist angle so that an innerdiameter of the sheath is decreased in the deployed configuration. Thetwist angle may be about 5 degrees or more, about 8 degrees or more,about 10 degrees or more, about 12 degrees or more, or about 15 degreesor more. The twist angle may be about 90 degrees or less, about 60degrees or less, about 45 degrees or less, about 30 or less, about 25 orless, or about 20 degrees or less. The amount of twist may be limited bya torsional limiter.

A torsional limiter may be any device that may limit the angle that thesheath may be twisted in an insertion configuration, a deployedconfiguration, or any configuration therebetween. A torsional limitermay be a portion of the distal collar, the proximal collar, or both. Atorsional limiter may be one or more cuts, one or more absences ofmaterial, one or more notches, or a combination thereof in a sheath thata portion of, a projection from, or both of a core wire, a proximalcollar, a distal collar, or both extend from and into the sheath, orvice versa so that the sheath, the core wire, the distal collar, theproximal collar, or a combination thereof may only be rotated apredetermined distance. The torsional limiter may be used to lock thetwist angle once a predetermined twist angle is achieved. For example,the core wire, the distal collar, the proximal collar, the sheath, or acombination thereof may be twisted to one of the one or more notches,the one or more cuts, the one or more absences of material, or acombination thereof and locked within, held in place by, or both afriction fit, a mechanical interlock, or both by a portion of the corewire, the proximal collar, the distal collar, the sheath, or acombination thereof connecting an adjacent component. The amount oftwist may be dependent upon the number of expandable members in eachsegment.

A number of expandable members between circumferentially spacedapertures, or slits, in a deployed state can be increased by increasingthe number of longitudinally spaced segments, particularly iflongitudinally adjacent expandable members are angularly offset fromeach other in a circumferential direction. With relatively moreexpandable members available by having a plurality of longitudinallyspaced segments, damage to a few strands (e.g., damage that can occurduring a surgical procedure) may have less impact on the blockingcapacity of the expanded component as compared to an embodiment havingrelative fewer strands. A sheath may have one or more expandablesegments along a longitudinal axis of the sheath. Preferably, the sheathhas a plurality of expandable segments along a longitudinal axis of thesheath. The sheath may have 1 or more, 2 or more, preferably 3 or more,more preferably 4 or more, or even more preferably about 5 or moreexpandable segments along a longitudinal axis of the sheath. The sheathmay even have 6, 7, 8, 9, or 10 expandable segments. Each expandablesegment may include a group of expandable members.

Each group of slits may have a length and thus each group of expandablemembers (i.e., petals in the deployed state) may have substantially thesame length. Preferably the length of each group of slits and each groupof expandable members is substantially the same. More preferably, eachgroup of slits around the outside of the sheath has the same length inthe insertion configuration and the deployed configuration. The lengthof each group of slits may vary depending on the desired cross-sectionaldistance of a lumen (e.g., diameter). The length of each group of slitsmay vary from segment to segment. For example, if the lumen is 10 mm incross-sectional length then at least one of the groups of petalscorresponding to the slits may have a length in the insertionconfiguration of about 10 mm. Thus, for example, upon buckling thepetals corresponding to the slits may extend about 5 mm from each sideso that the deployed cross-sectional length of the sheath is about 10mm. In another example one group of petals corresponding to slits in onesegment may have a length of 10 mm and another group of slits in anothersegment may have a length of about 9 mm. The expandable members may havea ratio of an insertion configuration longitudinal length to a deployedconfiguration cross-sectional length. The ratio may be any ratio so thatin the insertion configuration the ARD may pass by debris in a lumen andso that when deployed the ARD prevents the debris from being movedretrograde in a lumen. The ratio of insertion configuration longitudinallength to deployed configuration cross-sectional length may be about 1:2or more, about 1:5 or more, about 1:7 or more, preferably about 1:8 ormore, more preferably about 1:9 or more, or most preferably about 1:10or more. The ratio of insertion configuration cross-sectional length todeployed configuration cross-sectional length (e.g., ratio of expansion)may be about 1:20 or less, about 1:15 or less, or about 1:12 or less.However, one segment may have a ratio from about 1:8 to about 1:9 andanother ratio may have a ratio from about 1:9 to about 1:10. The longerthe length of each of the groups of expandable members in the insertionconfiguration may make the expandable members more susceptible tobuckling. However, each of the expandable members may include one ormore buckling features.

The expandable members may include one or more buckling features. Theone or more buckling features may be any feature that weakens all or aportion of the expandable members so that the expandable members buckleat the buckling feature forming petals. The buckling feature may be anabsence of material so that the structural integrity of the expandablemember is lower at the buckling feature. The buckling feature may be anadditional feature or device that is added to an expandable member sothat the expandable member buckles, folds, bends, or a combinationthereof at a predetermined location. Preferably, the buckling feature isa weakening of the one or more expandable members so that the expandablemembers bend, fold, or buckle at a predetermined location. The bucklingfeatures may be created by adding a hole, removing material from athickness of the expandable members, removing material from a width ofthe expandable members, scoring all or a portion of the expandablemember, including a window in a portion of the expandable member,cutting the expandable members and connecting back together with anothermaterial, or a combination thereof. The one or more buckling featuresmay be oriented so that the expandable segments buckle in a specificorder. For example, the bucking features may have more material removedin the groups of expandable members located near the proximate endregion, the distal end region, the intermediate region, or a combinationthereof. The length of the expandable members may dictate the bucklingorder of the expandable members. For example, the longest expandablemembers may buckle first. The width of the expandable members maydictate the buckling order. For example, the thinnest expandable membersmay buckle first. The buckling sequence may be determined by length,width, thickness, number of buckling features, location of the bucklingfeatures, or a combination thereof.

The sheath may be supported by and/or substantially wrapped around oneor more adjoining structures that assist in insertion, deployment,retraction, or a combination thereof. The sheath may have one or morecore wires that extend through a hollow interior region of the sheath.The one or more core wires may be any device that provides support tothe sheath; assists in inserting the sheath; assists in deployment ofthe anti-retropulsion device; assists in retraction of the sheathassists in rotation of the sheath and/or one or more expandable members;or a combination thereof. The one or more core wires may be any materialthat is rigid or has a longitudinal strength so that the core wire maybe used to move a sheath along its longitudinal axis. The one or morecore wires may be a braided material. The one or more core wires may betwo or more longitudinal wires that are substantially parallel alongtheir respective longitudinal axes. The one or more core wires may bemade of any material that is biocompatible. The one or more core wiresmay be made of a natural material, a synthetic material, a polymer, aplastic, a metal, nylon, stainless steel, or a combination thereof. Theone or more core wires may be a guidewire that is found in an endoscopeand the sheath may fit over the guidewire so that the sheath may bemoved to a predetermined position. The one or more core wires may beconnected to the sheath by one or more collars.

The one or more collars may be located at any location on the sheath,the one or more core wires, or both so that the one or more collarsassist in holding the sheath on the one or more core wires, deployingthe ARD, inserting the ARD, contracting the ARD, rotating all or aportion of the sheath, or a combination thereof. The one or more collarsmay be fixed relative to the insertion cone, the sheath, the core wire,or a combination thereof. The one or more collars may be movablerelative to the sheath, the guidewire, the insertion cone or acombination thereof. Preferably, at least one collar is fixed relativeto both the sheath and the core wire and at least one collar is moveablerelative to the core wire. For example, a collar on one end may be fixedand when the core wire is pulled in a direction opposite to theinsertion direction, the movable collar may move along the longitudinalaxis of the core wire towards the fixed collar, or vice versa so thatthe expandable members are expanded. One or more collars may be locatedin a distal end region (i.e., distal to the user), a proximal end region(i.e., proximal to the user), an intermediate region (i.e., between thedistal end region and the proximal end region), or a combinationthereof. Preferably, at least one collar is located in a distal endregion (i.e., distal collar) and at least one collar is located in theproximal end region (i.e., proximal collar). The one or more collars maybe any device that is biocompatible and assist in holding the sheath,the core wire, or both. The one or more collars may be crimped,connected, folded, snapped, glued, welded, mechanically interlocked, ora combination thereof to form a fixed connection. The one or moremovable collars may be the non-expandable portion of the sheath. Forexample, the portion of the sheath that is free of slits may form themovable collars. The one or more movable collars may bond one or morefiber strands, one or more petals, one or more expandable members, or acombination thereof together so that the sheath is formed. The one ormore movable collars may form a friction fit with the core wire so thatduring installation the one or more movable collars move with the sheathand upon a retraction of the core wire, the moveable collar slips sothat the ARD may be deployed. The one or more collars may be made of thesame material as the sheath, the core wire, or both. The one or moremovable collars may be attached to the one or more fiber strands, one ormore petals, one or more expandable members, or a combination thereof byadhesion bonding, wire wrapping, or the like or any combination thereof.One or more movable collars may connect one or both ends of the one ormore fiber strands, one or more petals, one or more expandable members,or a combination thereof so that each end may be twisted, one end may betwisted, or a combination of both. The one or more collars may be madeof a plastic, a polymer, an elastomeric, metal, a natural material, asynthetic material, or a combination thereof.

Other physical characteristics of an ARD tending to cause a device tomechanically deform or actuate are also possible. For example, somematerials exhibit piezo-electric characteristics that tend to cause thematerial to deform when the material is exposed to an electrical charge.In some embodiments, temperature changes can also cause a device toradially (and circumferentially) expand from an insertion state to adeployed state.

Grip tubes may be provided at the proximal end of the device that wouldbe connected to both the outer sheath and the core wire to provide agripping surface for rotating the core wire to launch the ARD. The griptube may be attached to the core wire and would extend beyond the griptube attached to the sheath, such that a user would be able to grasp andhold the grip tube attached to the sheath and rotate the grip tubeattached to the core wire to deploy the ARD. The grip tube may be anydevice that a user may grip so that the sheath, the core wire, or bothmay be rotated. The grip tube may assist a user in twisting the corewire, the sheath, or both. The grip tube may be any device used tolaunch the ARD.

Various material compositions or forms, e.g., metal, plastic, polymertube, fiber glass, and natural or synthetic fiber (strand or woven), maybe suitable. A polymer, thin-walled tube, or a fabric material, may besuitable for some embodiments (e.g., a tubular structure having obliqueslits). A polymer that is less prone to damage by an applied laserenergy in relevant spectrum may be suitable. ARDs as disclosed hereincan be deployed by inducing a relative movement between a core member(e.g., a guide-wire) and a portion of the expandable portion of the ARD.In some instances, a proximal end of the expandable portion can be urgedin a distal direction, or a distal end of the expandable portion can beurged in a proximal direction, as by withdrawing the core member. Duringa surgical procedure for removing debris from a body lumen, a safetyguidewire can be placed in the lumen (e.g., ureter, via a uretero tube).The ARD can be positioned in the lumen using a technique similar toinserting a conventional guidewire. The ARD can have a hydrophilic,flexible tip sized to be able to pass between the debris and a nearbylumen wall.

The expandable portion of the ARD can be positioned distally relative tothe debris by a selected distance. Subsequent to being positioneddistally of the debris, the expandable portion of the ARD can beexpanded as described above. The radially expanded ARD can occupy asufficient volume and cross-sectional area of the lumen to prevent orsubstantially reduce the degree to which the debris can move in aretrograde direction during treatment or manipulation by the surgeon. Insome instances, such as those concerning the removal of ureteral stones,ARDs as disclosed herein can be used to reduce or prevent retrogrademovement of individual debris particles arising from breaking stoneshaving a characteristic length (e.g., a cross-sectional dimension) ofabout 5 mm or larger. Typically, stones smaller than about 4 mm can bepassed spontaneously without requiring ureteral lithotripsy. Typically,ureteral stones rarely have a characteristic length exceeding about 10mm. The expandable portions, the sheath, the core wire, or a combinationthereof may include one or more surface markings.

The surface marking may be any marking on the ARD that assists a user indeploying, retracting, inserting, or a combination thereof the device.The surface markings may indicate the amount of circumferential openingof the expandable portions that has occurred, the length of core wirethat has been removed, the amount of twisting of the core wire, theamount of twisting of the sheath, or a combination thereof. The surfacemarkings may be one or a series of marks that indicate the position ofthe ARD, the state of the ARD, or both.

The ARD of the teachings herein may be transformed into a configurationcharacterized as being three-dimensional (3-D), as shown in FIG. 2, forexample. Such a 1-D (see FIG. 1) to a 3-D (see FIG. 2) transformationcan be accomplished by shortening a distance between opposed ends of thetubular structure, as described more fully below and shown by way ofexample in FIG. 9A-9K.

Some innovative ARDs can have a physical configuration in a deployedstate that wholly or partially forms a temporary, removable barrierbehind (e.g., distally positioned relative to) a body of debris (e.g., astone) in a body lumen. As shown in FIG. 1, the ARD 10 and theexpandable portion 20 of the sheath may have a slim elongateconfiguration suitable to pass through a gap between a stone (not shown)and surrounding anatomy (e.g., a lumen wall, not shown). The expandableportion 20 can be positioned behind (distally of) the debris and cantransform from the insertion state 100, as shown in FIG. 1, to adeployed state 110, as shown in FIG. 2, as by urging the distal collar12 and the proximal collar 13 of the expandable portion 20 toward eachother along the core wire 11 (e.g., through mechanical-, pneumatic-,chemical, or temperature-induced loading).

As is illustrated in FIGS. 1 and 3 a sheath 14 includes a non-expandableportion 21 proximate to the proximal end region 28 and distal end region26. The sheath 14 includes an expandable portion 20 having a proximal(to the user) end region 28 that is affixed to the proximal collar 13,and the distal end region 26 of the expandable portion 20 that can beconnected to a core wire 11 via a distal collar 12 in the distal endregion 26. An intermediate region 30 is located between the distal endregion 26 and the proximal end region 28. The proximal collar 12 and/orthe distal collar 13 can move longitudinally along the longitudinal axis112. The device shown in FIGS. 1 and 3 can change its configuration whenthe structure is compressed along the longitudinal axis 112 (e.g., whenthe core wire 11 is drawn through the sheath 14), causing expandablemembers 22 of the structure to buckle and expand radially outward,forming “petals” 34 (see FIG. 2) from the buckled members positionedbetween circumferentially adjacent slits 32.

As shown in FIG. 3, the sheath 14 has an expandable portion 20 and anon-expandable portion 21 configured to overlie a core, e.g., aguidewire 11 (as is shown in FIG. 1). The guidewire 11 can extendlongitudinally through a hollow interior region 16 of the sheath 14. Thesheath 14 extends between a distal end region 26 and a proximal endregion 28. The expandable portion 20 is comprised of one or moreexpandable segments 24 (i.e., five) that are positioned between thedistal end region 26 and the proximal end region 28 of the expandableportion 20. The longitudinally adjacent expandable segments 24 can belongitudinally spaced from each other by respective intermediate collars18.

In FIG. 3, the sheath 14 longitudinally alternates between contiguous(e.g., not expandable in a radial direction) collars 18 and slit wallsdefining separate expandable members 22 configured to expand in a radialdirection upon buckling under a longitudinally compressive load appliedto the sheath 14. Such longitudinal spacing between expandable segments24 can be beneficial but is not essential.

As illustrated in FIG. 5 and shown in the sequence of images shown inFIG. 9, urging the distal collar 12 and the proximal collar 13 (FIGS. 5and 6) toward each other can urge the respective distal end region 26and proximal end region 28 of the expandable portion 20 toward towardeach other, placing the expandable portion 20, and each of thecorresponding expandable segments 24 in compression. When a sufficientcompressive load is applied to the expandable portion 20, at least oneof the expandable members 22 in one of the expandable segments 24 willbuckle. The sequence of images in FIGS. 10A-10K shows severalintermediate states of buckling of the expandable segments 24. Althoughthe expandable member 22 may buckle inwardly at the onset of buckling(e.g. under a critical buckling load), the guidewire 11 (or other memberpositioned in the hollow interior region 16) will tend to limit theextent of inward buckling, causing the expandable member to eventuallybuckle, and expand, radially outwardly.

As a given expandable member 22 buckles, the member's resistance to thecompressive load substantially drops, transferring excess compressiveloading to adjacent expandable members 22. As a critical buckling loadis applied to each expandable member, the respective expandable memberwill buckle (eventually in a radially outward direction as justdescribed), transforming the geometric configuration of the respectiveexpandable segments 24 from a 1-D, insertion state as shown in FIGS. 1and 3 to a 3-D, deployed state as shown in FIGS. 2, 4A-4B and 5.

The distal end region 26 is positioned adjacent a distal collar 12 andthe proximal end 28 is positioned adjacent a proximal collar 13. Thedistal collar 12 is immovable relative to (e.g., affixed to) theguidewire 11, and the proximal collar 13 can be longitudinally movablerelative to the guidewire. In other embodiments, the distal collar canbe longitudinally movable relative to the guidewire 11, and the proximalcollar 13 can be immovable relative to the guidewire.

The components shown in, for example, FIGS. 1 through 9A-9K and10A1-10D3, have a number of longitudinally spaced, expandable segments.The pattern of circumferential separation of the members (e.g., partlyhelical apertures between adjacent members) is such that a proximal endof a given helical slit is circumferentially offset from an adjacentdistal end of another helical slit by a selected circumferential angle(e.g., from one segment to the next segment). Each of the distal collar12, the proximal collar 13 and the intermediate collars 18 are separateand distinct components from each other and the expandable segments 24.Alternatively, one or more of the distal collar 12, the proximal collar13, and the intermediate collars 18 form a unitary construction with theexpandable segments 24. FIG. 3 illustrates one example of an expandableportion 20 having a unitary construction with juxtaposed expandablesegments 24 spaced from each other by respective intermediate collars18.

Each expandable segment 24 shown in FIG. 3 defines a respectiveplurality of oblique slits 32 extending between a segment proximal endregion 56 and a segment distal end region 54 of the respectiveexpandable segments 24. Each slit 32 extends at an oblique anglerelative to a longitudinal axis 112 of the hollow interior 16. Eachoblique slit 32 partially defines a helically shaped aperture extendingthrough the annular wall of the expandable portion 20. An expandablemember 22 is defined between adjacent slits 32.

FIG. 4A shows a perspective view of expandable portion 20 in a deployedstate 110. Each expandable segment 24 defines a plurality ofcircumferentially spaced expandable members 22 forming petals 34. Eachpetal 34 includes an upper petal portion 36 and a lower petal portion38, which are twisted relative to each other as shown by arrows 114.FIG. 4B illustrates a top view of FIG. 4A. The hollow interior region 16is shown extending through the sheath 14, and the petals 34 fill thecircumference so that there are no longitudinal gaps through the sheath14.

The twist 114 of the petals 34 in a single expandable segment 24 isfurther illustrated between FIG. 9J to FIG. 9K, an expandable member 22twists and expands circumferentially to form a “petal” 34 so that eachrespective upper petal portion 36 and lower petal portion 38 arecircumferentially offset from each other.

FIGS. 5 and 6 illustrate the ARD 2 during a change from an insertionstate 100 (see FIG. 6) to a deployed state 110 (see FIG. 5). Once theARD 2 is fully inserted through a gap (not shown) using the insertioncone 60 the core wire 11 is retracted and the proximal collar 13 ismoved towards the distal collar 12 of the insertion cone 60. The corewire 11 is twisted so that the petals 34 twist.

FIGS. 7 and 8 illustrate several details of innovative ARDs. FIGS. 10through 13 illustrate examples of such devices in a deployed state. InFIG. 7, the expandable portion has five longitudinally spaced expandablesegments 24, with each segment defining six oblique slitscircumferentially spaced from each other by about 60°. The proximal end52 and the distal end 50 of each adjacent oblique slit 32 arecircumferentially offset from each other by about 60°, although othercircumferential offsets are possible. For example, a circumferentialoffset between the distal end and the proximal end of a given obliqueslit can range between about 0° and about 180°, such as between about40° and about 90°, with some embodiments having an offset measuringbetween about 60° and about 72°. Each of the expandable segments 24 ofFIG. 7 have a different length such that the lengths (L1, L2, L3, L4,and L5) each decrease from the distal end region 26 to the proximal endregion 28. The proximal end of an oblique slit can be circumferentiallyoffset from the distal end of a longitudinally adjacent oblique slit. Asillustrated the circumferential offset varies from β1 to β2 to β3 and toβ4 from the distal end region 26 to proximal end region 28 as the slits32 of each respective expandable segment 24 are varied. In someinstances, the offset (β) between longitudinally spaced oblique slitscan range between about 0° and about ½ of the circumferential spacingbetween adjacent slits in a given expandable segment. For example, inFIG. 7, adjacent slits are circumferentially spaced from each other byabout 60°. In this example, longitudinally spaced slits can becircumferentially offset from each other by between about 0° and about30°

Each of the expandable segments 24 of FIG. 8 are the same length (L).Further, the circumferential offset between a proximal end 52 and adistal end 50 of two adjacent slits 32 is less when compared to FIG. 7.Thus, β1′ has the same angle and same offset above the longitudinal axisand β2′ is offset below the axis so that when deployed the ARD fills abody lumen.

FIG. 9A through 9K illustrates a sequence of transformation of oneexpandable segment 24 from an insertion state 100 to a fully deployedstate 110. As shown in FIG. 9A, the sheath 14 includes a distal collar12 and a proximal collar 13 with a plurality of expandable members 22therebetween that represent one expandable segment 24. Each expandablemember 22 includes a buckling feature 62 so that each expandable member22 buckles at a predetermined location. FIGS. 9H through 9I demonstratethe transformation of each segment from a plurality of expandable member22 to a plurality of petals 34. In FIG. 9J when the expandable member 22is buckled and formed into a petal 34 the upper petal portion 36 istwisted in the direction 114 relative to the lower petal portion 38.

FIGS. 10A1-10D3 illustrate a number of alternative configurations ofexpandable segments 24 in a deployed (expanded) state. In FIG. 10, eachrow of images depicts a selected number and relative configuration ofexpandable segments. For example, each in the first row of images A1,B1, C1, D1 depicts an expandable portion 20 having a single expandablesegment 24.

Each in the second row of images A2, B2, C2, D2 depicts an expandableportion 20 having five longitudinally spaced expandable segments 24.Each expandable segment 24 has a unique length. An expandable portion 20of an ARD having a plurality of different-length expandable segments canallow for a more controlled expansion of the expandable portion. Forexample, a longer expandable segment will typically buckle (e.g.,expand) under a lower compressive load relative to the load under whicha shorter expandable segment will buckle. Accordingly, as compressiveloading of an expandable portion of an ARD increases, the respectivelydifferent-length segments will tend to expand sequentially from longersegments to shorter segments. In one embodiment, the expandable segments24 successively increase in length from the distal (shortest) expandablesegment 24 to the proximal (longest) expandable segment. As eachend-elevation view (from a distal position looking toward the distal endof the respective radially expanded ARDs) of FIGS. 10A2, 10B2, 10C2 and10D2 depict, the resulting configuration of the ARD in the deployedstate can be somewhat cone-like.

A sequence of buckling among a plurality of expandable segments can becontrolled using other approaches. For example, a portion of one or moreexpandable members 22 in each respective expandable segment 24 can beremoved to reduce a corresponding critical buckling load of each of theone or more expandable members. Under such an approach, relatively morematerial can be removed from each successive expandable segment (e.g.,to form a narrow “waist” in each segment) according to a selectedbuckling sequence, with the segments having more material removedtypically buckling under relatively lower compressive loads.

Approaches for controlling a sequence of buckling among a plurality ofexpandable segments can be combined. For example, each expandablesegment can have a corresponding length different from a length of oneor more other expandable segments, and material can be removed from oneor more expandable members corresponding to a given expandable segmentto define a waist.

Each in the third column of images A3, B3, C3, D3 depict a respectiveexpandable portion having five expandable segments of substantiallyidentical length.

Each row (e.g., A1, B1, C1, D1) of images in FIG. 10 depicts expandableportions having a selected number and configuration of oblique slits(and a corresponding number and configuration of expandable membersbetween adjacent oblique slits). Each expandable segment in Row A (i.e.,images A1, A2, A3) has six oblique slits equally spaced from each othercircumferentially (i.e., spaced from each other at 60°). As well, eachrespective distal end corresponding to each oblique slit in Column A iscircumferentially offset from the corresponding proximal end by 60°.

Each expandable segment in Row B (i.e., images B1, B2, B3) has sixoblique slits equally spaced from each other circumferentially (i.e.,spaced from each other at 60°). As well, each respective distal endcorresponding to each oblique slit in Row B is circumferentially offsetfrom the corresponding proximal end by 120°.

Each expandable segment in Row C (i.e., images C1, C2, C3) has fiveoblique slits equally spaced from each other circumferentially (i.e.,spaced from each other at 72°). As well, each respective distal endcorresponding to each oblique slit in Row C is circumferentially offsetfrom the corresponding proximal end by 72°.

Each expandable segment in Row D (i.e., images D1, D2, D3) has sixoblique slits equally spaced from each other circumferentially (i.e.,spaced from each other at 60°). As well, each respective distal endcorresponding to each oblique slit in Row D is circumferentially offsetfrom the corresponding proximal end by 72°. The expandable portion ofthe ARD shown in Row D is configured as a sheath that can overlie asheathed guidewire (e.g., a guidewire having a sheath member positionedbetween the expandable ARD and the guidewire). For example, in theinsertion state, the expandable portion shown in Row D has an outerdiameter of about 5.1 Fr.

In contrast, the embodiments shown in Rows A, B and C are configured asrespective guidewire sheaths. For example, the embodiments shown in RowsA, B and C have an outer diameter of about 3 Fr., and are configured todirectly overlie a guidewire (e.g., without a sheath positioned betweenthe expandable portion of the ARD and the guidewire).

FIG. 11 illustrates an ARD 2 having an insertion cone 60 with a hollowinterior region 16 so that the ARD 2 can be located on a guidewire (notshown) and the guidewire can extend through the ARD 2. As illustrated,each of the petals 34 has substantially the same length.

FIGS. 12 and 13 show representative isometric views of expandableportions of ARDs having a variation in length of the expandablesegments. The petals 34 of FIG. 13 have a length L1 at a proximal endregion 28 that is longer than the petals at the distal end region 26having a length L5.

FIG. 14 illustrates one expandable segment 24 having a hollow interiorregion 16 and expandable members 22 including one possible example of abuckling feature 62. The buckling feature 62 as illustrated has materialremoved from the edges of each expandable member 22.

FIG. 15 illustrates an example of an ARD 2 including a narrow wasteregion 64 formed by an intermediate collar 18 being between each petal34. As illustrated, the insertion cone 60 acts as the distal collar 12.

FIGS. 16 through 17 illustrate an alternative embodiment of anexpandable portion 20 of a sheath 14. As shown in FIG. 16 the ARD 2 isin the insertion state 100. The expandable portion 20 has a plurality offiber strands 41 extending between a proximal collar 13 and a distalcollar 12. The proximal end of each respective fiber can be fixedlycoupled to the proximal collar 13, and the distal end of each respectivefiber can be fixedly coupled to the distal collar 12. The distal collar12 can be fixedly coupled to the guidewire 11. The proximal collar 13can be longitudinally moveable relative to the guidewire 11 such thatthe proximal collar 13 and the distal collar 12 can be urged toward andapart from each other. As shown in FIG. 17, drawing the proximal collar13 toward the distal collar 12 can cause the plurality of fiber strands41 to buckle and expand radially outwardly. Although the fibers areshown as being discretely and orderly buckled in FIG. 17 to form adeployed state 110, as a result of limitations of the software used todevelop and render a three-dimensional model of the expandable portion20, it is anticipated that the fiber strands 41 are likely to buckle ina somewhat less orderly manner, and possibly become intertwined witheach other when radially expanded.

In FIGS. 16 and 17, the plurality of fiber strands 41 have an outerdiameter of about 1 mm. In one contemplated embodiment 72 individualfibers are arranged in two concentric rings of fibers (i.e., one ring offibers concentrically positioned relative to the other ring of fibers).The pair of concentric rings of fibers can define a wall thickness ofabout 0.1 mm. In other contemplated embodiments, several (e.g., morethan about 10 and fewer than about 100) fibers can be arranged to forman annular ring of fibers. A thickness of the ring (e.g., a “wall”thickness) can measure less than 1 mm, e.g., less than about 0.5 mm,with about 0.1 mm being but one example.

With suitable materials (e.g., combining a suitable amount offlexibility and column strength), a mesh configuration can alsotransform from a “long and slim” configuration to a “wide and short”configuration. FIG. 18 shows such an embodiment.

With a mesh structure as shown in FIG. 18, with a distal collar 12 and aproximate collar 13 with sheath 14 there between forming a middlesection. The expansion of the middle section (e.g., when the opposedends are urged together) is generally more constrained and limitedcompared to the device shown in FIGS. 5, 6 and 7, above. Nonetheless,even with a very soft, pliable material, a mesh structure can reduce alikelihood of tangling between expanded members. With the principlesdisclosed herein, it is possible to design, construct and use a widevariety of apparatus configured to reduce or eliminate retropulsion of abody or other debris within a body lumen during a surgical procedure.

This disclosure makes reference to the accompanying drawings which forma part hereof, wherein like numerals designate like parts throughout.The drawings illustrate specific embodiments, but other embodiments maybe formed and structural changes may be made without departing from theintended scope of this disclosure. Directions and references (e.g., up,down, top, bottom, left, right, rearward, forward, etc.) may be used tofacilitate discussion of the drawings but are not intended to belimiting. For example, certain terms may be used such as “up,” “down,”,“upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and thelike. These terms are used, where applicable, to provide some clarity ofdescription when dealing with relative relationships, particularly withrespect to the illustrated embodiments. Such terms are not, however,intended to imply absolute relationships, positions, and/ororientations. For example, with respect to an object, an “upper” surfacecan become a “lower” surface simply by turning the object over.Nevertheless, it is still the same surface and the object remains thesame. As used herein, “and/or” means “and” as well as “and” and “or.”

Accordingly, this detailed description shall not be construed in alimiting sense, and following a review of this disclosure, those ofordinary skill in the art will appreciate the wide variety of imagingsystems that can be devised and constructed using the various conceptsdescribed herein. Moreover, those of ordinary skill in the art willappreciate that the exemplary embodiments disclosed herein can beadapted to various configurations without departing from the disclosedconcepts. Thus, in view of the many possible embodiments to which thedisclosed principles can be applied, it should be recognized that theabove-described embodiments are only examples and should not be taken aslimiting in scope. I therefore reserve the right claim as my inventionsall that come within the scope and spirit of this disclosure.

Any numerical values recited herein include all values from the lowervalue to the upper value in increments of one unit provided that thereis a separation of at least 2 units between any lower value and anyhigher value. As an example, if it is stated that the amount of acomponent or a value of a process variable such as, for example,temperature, pressure, time and the like is, for example, from 1 to 90,preferably from 20 to 80, more preferably from 30 to 70, it is intendedthat values such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 etc. areexpressly enumerated in this specification. For values which are lessthan one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 asappropriate. These are only examples of what is specifically intendedand all possible combinations of numerical values between the lowestvalue and the highest value enumerated are to be considered to beexpressly stated in this application in a similar manner.

Unless otherwise stated, all ranges include both endpoints and allnumbers between the endpoints. The use of “about” or “approximately” inconnection with a range applies to both ends of the range. Thus, “about20 to 30” is intended to cover “about 20 to about 30”, inclusive of atleast the specified endpoints.

The disclosures of all articles and references, including patentapplications and publications, are incorporated by reference for allpurposes. The term “consisting essentially of” to describe a combinationshall include the elements, ingredients, components or steps identified,and such other elements ingredients, components or steps that do notmaterially affect the basic and novel characteristics of thecombination. The use of the terms “comprising” or “including” todescribe combinations of elements, ingredients, components or stepsherein also contemplates embodiments that consist essentially of theelements, ingredients, components or steps. By use of the term “may”herein, it is intended that any described attributes that “may” beincluded are optional.

Plural elements, ingredients, components or steps can be provided by asingle integrated element, ingredient, component or step. Alternatively,a single integrated element, ingredient, component or step might bedivided into separate plural elements, ingredients, components or steps.The disclosure of “a” or “one” to describe an element, ingredient,component or step is not intended to foreclose additional elements,ingredients, components or steps.

It is understood that the above description is intended to beillustrative and not restrictive. Many embodiments as well as manyapplications besides the examples provided will be apparent to those ofskill in the art upon reading the above description. The scope of theteachings should, therefore, be determined not with reference to theabove description, but should instead be determined with reference tothe appended claims, along with the full scope of equivalents to whichsuch claims are entitled. The disclosures of all articles andreferences, including patent applications and publications, areincorporated by reference for all purposes. The omission in thefollowing claims of any aspect of subject matter that is disclosedherein is not a disclaimer of such subject matter, nor should it beregarded that the inventors did not consider such subject matter to bepart of the disclosed inventive subject matter.

I currently claim:
 1. An anti-retropulsion device comprising: aplurality of expandable segments extending along a longitudinal axis; adistal collar positioned distally of the expandable segments; and aproximal collar positioned proximally of the expandable segments;wherein the expandable segments have a corresponding plurality ofexpandable members, and wherein each of the expandable members areconfigured to expand or contract radially and circumferentially incorrespondence with a change in spacing between the distal collar andthe proximal collar, and wherein the anti-retropulsion device isconfigured to be inserted into a body lumen and when the expandablemembers expand in the body lumen, the expandable members in one of theexpandable segments are circumferentially offset relative to theexpandable members in another one of the expandable segments such thatformation of longitudinally extending gaps between the expandablemembers is prevented so that debris are prevented from moving in thebody lumen past the expandable members.
 2. The anti-retropulsion deviceaccording to claim 1, further comprising a plurality of intermediatecollars, wherein the plurality of expandable segments is juxtaposed withthe plurality of intermediate collars such that each expandable: segmentis longitudinally spaced from another expandable segment and at leastone of the plurality of intermediate collars is positioned betweenlongitudinally adjacent expandable segments.
 3. The anti-retropulsiondevice according to claim 1, wherein each of the expandable segments hasa corresponding plurality of expandable members, wherein each of theexpandable members is configured to expand or contract along twocoordinate directions in correspondence with a change in spacing betweenthe distal collar and the proximal collar.
 4. The anti-retropulsiondevice according to claim 1, wherein the expandable segment comprises asheath having a generally annular cross-section and extending generallycoaxially with the longitudinal axis, wherein each of the expandablemembers is defined by a pair of oblique slits extending through thesheath.
 5. The anti-retropulsion device according to claim 4, furthercomprising a core wire extending through the sheath, wherein the distalcollar is so fixedly coupled to a distal portion of the core wire as tosubstantially prevent relative movement between the distal collar andthe core wire, and wherein the proximal collar is longitudinallyslidable along the core wire.
 6. The anti-retropulsion device accordingto claim 5, wherein the sheath comprises a first sheath and theanti-retropulsion device further comprises a second sheath positionedbetween the core wire and the first sheath.
 7. The anti-retropulsiondevice according to claim 1, wherein the expandable members expand andform petals, each petal includes an upper petal portion and a lowerpetal portion, and the upper petal portion is twisted relative to thelower petal portion.
 8. The anti-retropulsion device according to claim1, wherein the expandable members are sufficiently elastic so that whenthe anti-retropulsion device is inserted into the body lumen and theexpandable members expand, the expandable members contact the body lumenand at least partially deform.
 9. The anti-retropulsion device accordingto claim 8, wherein the expandable members are made of a polymer, anelastomer, a polyethylene, polyethylene terephthalate, a polyamide, or acombination thereof.
 10. The anti-retropulsion device according to claim1, wherein the anti-retropulsion device is configured to be twisted sothat angles are formed between adjacent expandable members.
 11. Theanti-retropulsion device according to claim 1, wherein the expandablemembers in the one of the expandable segments relative to the expandablemembers in the another one of the expandable segments arecircumferentially offset by an angle between 5 degrees and 30 degrees.12. The anti-retropulsion device according to claim 1, wherein two ormore of the expandable segments have a different length.
 13. Theanti-retropulsion device according to claim 12, wherein the length ofeach expandable segment decreased form a distal end region to a proximalend region.
 14. An anti-retropulsion device comprising: an elongatetubular sleeve extending along a longitudinal axis defining an outerwall having: a proximal wall portion having an expandable segmentdefining a first plurality of apertures, each of the first plurality ofapertures having: a proximal end, and a distal end: a distal wallportion longitudinally spaced from the proximal wall portion, the distalwall portion having an expandable segment defining a second plurality ofapertures having; a proximal end, and a distal end; and an intermediatewall portion located between the proximal wall portion and the distalwall portion; wherein, the proximal end and the distal end of each ofthe first plurality of apertures, the second plurality of apertures, orboth are positionally offset in an ordinate direction; wherein each ofthe proximal ends of the second plurality of apertures are offset in anordinate direction from each of the distal ends of the first pluralityof apertures; and an apparatus configured to urge a distal end of theelongate tubular sleeve toward a proximal end of the elongate tubularsleeve to expand one or more expandable members defined by adjacentfirst apertures and adjacent second apertures, wherein theanti-retropulsion device is configured to be inserted into a body lumenso that when the expandable members expand the expandable members in oneof the expandable segments are circumferentially offset relative to theexpandable members in another one of the expandable segments such thatformation of longitudinally extending gaps in the body lumen isprevented.
 15. The anti-retropulsion device according to claim 14,wherein the intermediate wall portion includes at least a thirdplurality of apertures having: a proximal end and a distal end; whereineach of the proximal ends and the distal ends of the at least the thirdplurality of apertures are offset in an ordinate direction; and whereineach of the proximal ends of the third plurality of apertures are offsetin an ordinate direction from each of the distal ends of the firstplurality of apertures, the second plurality of apertures, or both, andwherein the expandable members are further defined between adjacentthird apertures.
 16. The anti-retropulsion device according to claim 15,wherein the first plurality of apertures, the second plurality ofapertures and the third plurality of apertures have a different length,and wherein the lengths of the first plurality of apertures and thesecond plurality of apertures decreases from the second plurality ofapertures to the first plurality of apertures.
 17. The anti-retropulsiondevice according to claim 14, wherein the expandable members expand andform petals, the petals are circumferential offset relative to oneanother so that the petals can prevent debris from moving in the bodylumen past the petals.
 18. The anti-retropulsion device according toclaim 17, wherein each petal includes an upper petal portion and a lowerpetal portion, and the upper petal portion is twisted relative to thelower petal portion.
 19. The anti-retropulsion device according to claim14, wherein the expandable members are sufficiently elastic so that whenthe expandable members expand in the body lumen, the expandable memberscontact the body lumen and at least partially deform.